Drier



Sept. 8, 1931. c. c. HERITAGE I DRIER Filed Feb. 19, 1926 2 Sheets-Sheet 1 patented Sept. 8, 1931 UNITED STATES PATENT OFFICE CLARK C. HERITAGE, O1 BUFFALO, NEW YORK, ASSIGNOR T NATIONAL ANILIHE & CHEMICAL 00., INC., 01 NEW YORK, N. Y., A CORPORATION OF NEW YORK DRIER Application filed February 19, 1826. Serial No. 89,317.

This invention relates to the drying of wet or moist material by the removal of liquid therefrom with the aid of heat. It relates more particularly to improvements in proc- 5 esses and apparatus for the vacuum drying of such material, and is especially concerned with the treatment of relatively small quantities of material. a

For small tonnage production, the usual vacuum drier of the horizontal rotary type has the objections of high initial cost and inefiicient operation. These objections arise from the fact that such a drier in a small size requires the same equipment and end con struction as one built for large scale operations, and the further fact that a large proportion of its heated surface is not utilized in the drying operation. Consequently it is customary to em loy drier pans when the uantity of material to be dried is too small or economical handlin in rotar driers; but these are attended y high la or costs, high losses in handling and slow operation.

According to the present invention, rela-- tively small batches are dried with comparativel short time cycles, low labor cost and free om from handlin losses. The invention presents the further eatures of inexpensive installation, long life with low maintenance, operation under an condition of pressure or vacuum, and capa ility of performing the additional operations of grinding, mixing and standardizing.

In brief, the process forming a part of the invention comprises elevating the material to be dried while in contact with asubstantially vertical surface, scraping the dried material from contact with the surface, and removing vapor formed in the drying of the material. I

The apparatus forming a art of'the invention consists of a vertical jac lr a rounded or sloping bottom, and a removable agitator suspended within the vessel, the agitator being of a type that shears dried material from the wall to afford an efiicient heat transfer to fresh material. With the vertical arrangement, the weight of the agitator is carried by the cover, its coaction with eted vessel with the vessel wall is uniform for the whole periphery, and the entire vessel circumference is utilized for the drying operation. This also permits the use of a cast iron construction with its attendant advantages.

In the accompanying drawings Fig. 1 is a top view of the drier; and.

Fig. 2 is a vertical axial section.

A container 1 having a round bottom 2 is provided with a jacket 3 inclosin the operaribbon type, formed to follow closely the container configuration and with the broad surface of the ribbon disposed at an angle to the axis of the agitator, thus providing an improved lifting and shearmg action. The lower end 11 of the ribbon is attached to the shaft, and arms 12, 13 and 14 extending from the shaft, support remaining portions of the agitator ribbon.

The container has a charging opening 15,

suitably closed and a vapor outlet 16 in the cover. Abottom discharge 17 is closed by a valve 18 whose stem 19 is threaded in a 'swiveled arm 20.

In the operation of the drier,'press cake or other material to be dried is charged through the opening 15, and the opening is closed. The agitator is started, and as it revolves, it first forces upwardly, or elevates, into contact with the inner surface of the vertical wall of the container the material to be dried lying near the wall. As the revolution of the agitator continues, the material is further elevated while in contact with said surface until the upper end of the agitator ribbon is reached, and then it falls back into the container. The wall is heated to a temperature suitable for dryingthe material, and the, heat transmitted by the wall of the container to the material, while it is being elevated in contact with the inner surface of said wall, causes liquid or moisture contained in it to vaporize. Vapor formed in the drying of the material is removed through the outlet 16 in any well known manner. The agitator blade, by reason of its angular disposition relative to the vessel wall, shears and scrapes off any moist or dried material which tends to adhere to the wall; it also forces said material toward its inner edge, from which said mate- 10 rial dro s back into the lower central The close contact of the agitator ribbon andgthe container wall prevents encrustations on' 'the wall which check the transfer of heat. It also serves to cause a grinding or pulverizing of the material as the aste or press cake approaches dryness, and results in a productof considerable fineness. This action and the completeness of the agitation render the invention useful for mixing other materials withthe press cake by grinding them together as, for example, for mixing common salt or Glaubers salt with dyestuifs.

The vertically arranged agitator and the bottom discharge in axial alignment combine in providin 'a drier that is quickly and completely emptied when the dr ing action is finished. It furthermore aifor s a construction that is readily cleaned for changing from one'product .to another. Obviously, the container and agitator axis need not be truly vertical as the structure is operable with various inclinations of the axis and the term substantiallyvertical is intended to in; clude such an angular disposition. With an inclined arrangement it ma be desirable to offset the discharge opening rom the axial line.

I claim:

1. In an apparatus for drying wet or moist material by the removal of liquid therefrom with the aid of heat, the combination of a vertical cylindrical wall, means for heating said wall to a drying temperature, means for elevating material to be dried into contact with said wall, and means for removing vapors formed in the drying of said material.

' 2. In an apparatus for drying wet or moist material by the removal of liquid therefrom with the aid of heat, the combination of a heated vertical cylindrical wall, a rotary spiral agitator in close contact with said wall for elevating material to be dried in contact with said wall, and means for removing vapors formed in the drying of said material. a

3. In an apparatus for drying wet or moist on material by the removal of liquid therefrom with the aid of heat, the combination of a heated vertical cylindrical wall, a rotary spiral agitator in close contact with said wall for elevating material to be dried in contact with said wall and for shearing dried material from contact with said well, and means for removing vapors formed in the drying of sad materia 4. In an apparatus for drying wet or moist material by the removal of liquid therefrom with the aid of heat, the combination of a closed container for the material to be dried having a vertical cylindrical wall, means for heating sa d wall to a drying temperature, a rotary spiral agitator for elevating the material while in contact with said wall, and an outlet in said cover for removing vapor formed in the drying of said material.

5. In an apparatus for drying wet or moist material by the removal of liquid therefrom with the aid of heat, the combination of a closed container for the material to be dried having a vertical cylindrical wall, a heating jacket for heating said wall to a drying temperature, a cover for said container, a. rotatable shaft suspended from said cover axially of said contalner, a spiral ribbon agitator mounted on said shaft in close contact with said wall for elevating said material while in contact with said wall, and an outlet in said cover for removing vapor formed in the dry ing of said material.

6. In an apparatus for drying wet or moist material by the removal of liquid therefrom with the aid of heat, the combination of a closed container for the material to be dried having a vertical cylindrical wall and a valve controlled bottom outlet, a heating jacket for heatin said wall to a drying temperature, a cover or said container, a rotary spiral ribbon agitator for elevating said material while in contact with said wall mounted in close contact with said wall and having the broad surface of said ribbon angularly disposed with respect to said wall, and an outlet in said cover for removing vapor formed in the drying of said material.

7. In an apparatus for drying wet or moist heated vertical cylindrical wall, a rotar spiral ribbon agitator in close contact with said wall for elevating the material to be dried in contact with the wall and having the broad surface of said ribbon angularly disposed with respect to the wall.

In testimony whereof I aflix my signature.

CLARK C. HERITAGE.

;material by the removal of liquid therefrom p with the aid of heat, the combination of a 

